KR100600685B1 - Physical quantity sensor - Google Patents

Abstract

The physical quantity sensor is configured using a plurality of piezoelectric sensors each having a first and second semiconductor layer for realizing a resistance and a terminal, and a conductive weighting portion associated with an opening in the insulating film for partially exposing the main surface of the substrate. Since the two semiconductor layers extend from the periphery of the opening on the insulating film to the inside of the opening and support the conductive weight portion in a floating state three-dimensionally, three-dimensional displacement can be realized. The capacitive electrode layer is arranged at the bottom of the opening on the main surface of the substrate to form a capacitance with the conductive weighting portion. The displacement of the conductive weighting portion is detected based on the resistance strain and the capacitance strain. Therefore, it is possible to detect physical quantities such as acceleration, vibration, and inclination with the reduced chip size.

Conductive weighting part, capacitive electrode layer, resistance strain, capacitance strain, piezoelectric sensor,

Description

Physical quantity sensor {PHYSICAL QUANTITY SENSOR}

1 is a perspective view showing an IC device provided with a physical quantity sensor according to a preferred embodiment of the present invention.

2 is a circuit diagram illustrating an equivalent circuit that simulates the actual operation of a physical quantity sensor.

3 is a cross-sectional view showing a first step relating to the formation of an insulating film in the method of manufacturing the IC device shown in FIG. 1;

4 is a cross-sectional view showing a second step relating to polysilicon deposition in the method of manufacturing the IC device shown in FIG. 1;

FIG. 5 is a sectional view showing a third step relating to patterning and deposition in the method of manufacturing the IC device shown in FIG. 1; FIG.

FIG. 6 is a sectional view showing a fourth step relating to passivation and opening formation in the method of manufacturing the IC device shown in FIG. 1; FIG.

FIG. 7 is a cross-sectional view showing a transistor related region with respect to the first step shown in FIG. 3; FIG.

8 is a cross-sectional view showing a transistor related region with respect to the second step shown in FIG.

9 is a cross-sectional view showing a transistor related region with respect to the third step shown in FIG. 5 and the fourth step shown in FIG.

Fig. 10 is a cross-sectional view showing a transistor related region related to insulating film formation and polysilicon deposition in a modification of the manufacturing method.

Fig. 11 is a cross-sectional view showing a transistor related region relating to polysilicon patterning and connection hole formation in a modification of the manufacturing method.

12 is a cross-sectional view showing a transistor related region relating to tungsten deposition and patterning in a modification of the manufacturing method.

13 is a perspective view showing a physical quantity sensor according to a second embodiment of the present invention.

Fig. 14 is a plan view showing the layout of circuit components arranged on the main surface of the substrate used for the piezoelectric sensor.

Fig. 15 is a perspective view showing a bearing sensor in which physical quantity sensors and magnetic sensors are arranged on the same substrate according to the third embodiment of the present invention.

FIG. 16 is a cross-sectional view similar to the third step shown in FIG. 5 and showing the manufacturing step for the bearing sensor shown in FIG. 15, wherein the magnetic sensor is formed simultaneously with the physical quantity sensor;

FIG. 17 is a cross-sectional view similar to the fourth step shown in FIG. 6 and showing a manufacturing step for the bearing sensor shown in FIG. 15, wherein the magnetic sensor is formed simultaneously with the physical quantity sensor;

<Brief description of the main parts of the drawing>

10: semiconductor substrate

12, 14, 18, 20: insulating film

16, 22X: capacitive electrode layer

20a: opening

20b: connection hole

22: polysilicon layer

22A: Piezoelectric Sensor

22a, 22b, 22c: semiconductor layer

24W: weight layer

22P, 22Q and 22R: Resistive Layer

26: interlayer insulation film

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a physical quantity sensor that detects physical quantities such as acceleration, vibration, and inclination in a two-dimensional or three-dimensional manner, and more particularly, to a capacitive piezoelectric sensor that can be manufactured according to a semiconductor manufacturing process.

This application claims priority to Japanese Patent Application No. 2004-31620, the contents of which are referred to in the present invention.

Conventionally, various types of piezoelectric sensors having the ability to detect acceleration in a three-dimensional manner have been developed, and an example of a piezoelectric sensor as shown in FIG. 14 is disclosed in Japanese Patent Application Laid-open No. S62-174978.

In the piezoelectric sensor shown in FIG. 14, the X-axis detector 2X, the Y-axis detector 3Y, and the Z-axis detector 4Z are arranged on the main surface of the substrate 1, and also above the detector 2X, Peripheral circuits 5 for processing the direction information formed by 3Y and 4Z are arranged. Here, both the X-axis direction and the Y-axis direction lie parallel to the main surface of the substrate 1 having a rectangular shape consisting of short side surfaces and long side surfaces, where the X axis direction is the short side surface of the substrate 1. And the Y-axis direction lies parallel to the long side of the substrate (1). The Z axis direction lies perpendicular to the main plane of the substrate 1, which also lies perpendicular to the X and Y axes, respectively.

The X-axis detector has three movable members 2a to 2c, each of which is cantilevered and of different lengths, and each of the leading ends of the movable members 2a to 2c realize its weighting function. In order to do that, the width is extended. The movable members 2a to 2c are respectively displaced in response to the acceleration applied in the X-axis direction, whereby the displacement of the longer one is increased. The Y-axis detector 3Y has three movable members 3a to 3c, each of which is cantilevered and different in length from each other, and each of the distal ends of the movable members 3a to 3c has a weighting function to realize its weighting function. The width is extended. The movable members 3a to 3c are each displaced in response to the acceleration applied in the Y-axis direction, and the displacement of the longer one is increased. Similarly, the Z-axis detector 4Z also has three movable members 4a to 4c, each of which is cantilevered, different in length from each other, and the tips of the movable members 4a to 4c are respectively The width is extended to realize the weighting function. The movable members 4a to 4c are each displaced in response to an acceleration applied thereto in the Z-axis direction, at which time the displacement of the longest one is increased.

All the movable members 2a-2c, 3a-3c, and 4a-4c are manufactured by etching the silicon material used for the substrate 1, where the base of each movable member is piezoresistance realized by diffusion resistance. Has Therefore, each movable member can convert the displacement into an electrical signal using a piezoresistor.

As described above, the conventionally known piezoelectric sensor has an X-axis detector 2X having movable members 2a-2c, which are particularly used for the detection of acceleration in the X-axis direction, and a movable member, which is particularly used for detection of the acceleration in the Y-axis direction. A Y-axis detector 3Y having (3a-3c) and a Z-axis detector 4Z having movable members 4a-4c, which are particularly used for detecting acceleration in the Z-axis direction, are provided on the main surface of the substrate 1. Designed to be arranged. This increases the total area occupied by the detectors 2X, 3Y, and 4Z, thereby increasing the size of the entire chip.

An object of the present invention is to provide a small physical quantity sensor (for example, a capacitive type piezoelectric sensor) capable of detecting physical quantities such as acceleration, vibration, and inclination in a two-dimensional or three-dimensional manner.

In a first aspect of the invention, a physical quantity sensor comprises a substrate; An insulating film having an opening formed to partially expose a main surface of the substrate; A plurality of piezoelectric sensors each having two terminals, each piezoelectric sensor being configured such that its sensing portion is arranged in the opening while being supported by the two terminals attached on the insulating film at different positions around the opening; The piezoelectric sensor includes a first semiconductor layer having a coiled winding pattern extending from the periphery of the opening to the inside of the opening, and a second semiconductor having a coiled winding pattern extending from the periphery of the insulating film to the inside of the opening. A layer and a conductive weighting portion interconnecting the inner ends of the first and second semiconductor layers in the opening, whereby the outer ends of the first and second semiconductor layers attached on the insulating film are connected to the two terminals. Used to form the conductive weighting portion supported by the first and second semiconductor layers in a floating state in the opening Realizing three-dimensional displacements; And a capacitive electrode layer arranged at the bottom of the opening on the main surface of the substrate to form a capacitance between the conductive weights, whereby the displacement of the conductive weights is dependent upon deformation of the resistance of the first and second semiconductors. It is to be detected based on the deformation of the dose.

In the above description, in the state where the main surface of the substrate is facing upward, the conductive weighting portion of the piezoelectric sensor is supported by the first and second semiconductor layers having a coil shape, thereby realizing three-dimensional displacement. That is, the conductive weight of the piezoelectric sensor is displaced in response to the 'horizontal' acceleration applied in parallel with the main surface of the substrate, and is also displaced in response to the 'vertical' acceleration applied in the vertical direction perpendicular to the main surface of the substrate. do. The displacement of the conductive weighting portion can be detected based on the resistance strain and the capacitance strain of the first and second semiconductor layers (due to the piezoelectric effect). Therefore, since the capacitive deformation does not occur in response to the horizontal acceleration but occurs in response to the vertical acceleration, it is possible to distinguish the direction of the acceleration applied in the horizontal direction or the vertical direction with respect to the capacitive deformation. This makes it possible to realize two-dimensional detection of a physical quantity such as acceleration by using one piezoelectric sensor, thereby reducing the total chip size of the physical quantity sensor.

In addition, it is further possible to provide a second capacitance electrode layer which makes a second capacitance in relation to the first and second semiconductor layers, wherein the displacement of the conductive weighting portion is detected in relation to the deformation of the second capacitance. That is, when acceleration is applied to the substrate in the X-axis direction or Y-axis direction on the main surface of the substrate, it is possible to distinguish the direction of acceleration in relation to the deformation of the capacitance, so that three-dimensional physical quantity detection can be realized.

In a second aspect of the invention, a physical quantity sensor comprises a substrate; An insulating film having an opening formed to partially expose a main surface of the substrate; A plurality of piezoelectric sensors each having two terminals and a sensing unit, wherein the sensing unit is supported in a floating state in the opening by two terminals fixed at different positions around the opening of the insulating film, each piezoelectric sensor being connected to the opening of the insulating film First and second semiconductor layers extending parallel to each other from the periphery to the inside of the opening, and conductive weights interconnecting the inner ends of the first and second semiconductor layers at the opening, thereby providing the first and the An outer end of the second semiconductor layer is fixed on the insulating film to form the two terminals, and the conductive weighting portion is supported by the first and second semiconductor layers to realize a three-dimensional displacement; A capacitor electrode layer arranged at a bottom of the opening on the main surface of the substrate to form a capacitance between the conductive weighting portion, whereby the displacement of the conductive weighting portion is dependent upon the resistance of the first and second semiconductor layers. Detected based on the deformation and deformation of the dose.

In the above description, in the state where the main surface of the substrate is facing upward, the conductive weighting portion of the piezoelectric sensor is supported by the first and second semiconductor layers, and the layers extend in parallel to each other, thereby providing three-dimensional displacement. It can be realized. When the first and second semiconductor layers extend in the Y-axis direction on the main surface of the substrate supported horizontally, and the substrate is rotated about an axis of rotation that lies parallel to the X-axis direction and is thus inclined, the conductive weighting portion of the substrate Displaced only in the direction perpendicular to the plane. When the substrate is rotated about and inclined with respect to another axis of rotation lying parallel to the Y axis direction, the conductive weights are bidirectionally displaced in the X axis direction and in a direction perpendicular to the main surface of the substrate. The above-described displacement of the conductive weight portion is detected based on the resistance strain and the capacitance strain of the first and second semiconductor layers. Compared to the resistive and capacitive deformations that occur when the substrate is inclined with respect to the axis of rotation lying parallel to the X axis direction, the resistive and capacitive deformations that occur when the substrate is inclined with respect to the axis of rotation lying parallel to the Y axis direction are more small. This operating principle makes it possible to detect the inclination angle and the inclination direction based on the resistance deformation and the capacitance deformation. Therefore, it is possible to detect physical quantities such as inclinations in a two-dimensional manner, thereby reducing the overall chip size.

In a third aspect of the invention, a physical quantity sensor comprises a substrate; An insulating film having an opening formed to partially expose a main surface of the substrate; A plurality of piezoelectric sensors each having a sensing portion and two terminals, the sensing portions being cantilevered in relation to the opening, each piezoelectric sensor extending in parallel to each other from the periphery of the opening of the insulating film to the inside of the opening; First and second semiconductor layers, and conductive weights interconnecting inner ends of the first and second semiconductor layers at the openings, whereby outer ends of the first and second semiconductor layers are connected to the two terminals. A conductive weighting portion supported by the first and second semiconductor layers to form a three-dimensional displacement; A plurality of capacitive electrode layers arranged at the bottom of the opening on the main surface of the substrate to form capacitances with the conductive weights, respectively, so that the displacement of the conductive weights is caused by the first and second semiconductor layers. It is detected based on the deformation of the resistance and the deformation of the capacitance.

In the above description, a plurality of piezoelectric sensors are each cantileveredly supported above the openings, and they extend inwardly from the various positions on the insulating film in the X-axis direction and the Y-axis direction, respectively. By combining a plurality of piezoelectric sensors each capable of detecting the inclination, it is possible to accurately detect the physical quantity in a two-dimensional manner. Since the sensing portions of the plurality of piezoelectric sensors are all arranged in a single opening, the overall chip size can be reduced.

As described above, the present invention realizes a compact physical quantity sensor that can reduce physical chip size to detect physical quantities such as acceleration, vibration, and inclination in a two-dimensional or three-dimensional manner. Since this physical quantity sensor is constructed using a capacitive type piezoelectric sensor basically composed of a semiconductor layer, it can be easily manufactured by a semiconductor manufacturing process. Therefore, the physical quantity sensor can be easily integrated together in the peripheral circuit or the signal processing circuit.

These and other objects, aspects, and embodiments of the invention will be described in more detail with reference to the accompanying drawings.

The present invention will be explained in more detail by way of examples below with reference to the accompanying drawings.

1 illustrates an IC device in which a physical quantity sensor according to a preferred embodiment of the present invention is installed.

In Fig. 1, the main surface of the semiconductor substrate 10 made of single crystal silicon is covered with an insulating film 12 made of silicon oxide, and an insulating film 14 made of silicon oxide is further formed thereon.

The capacitor electrode layer 16 made of metal or semiconductor is formed on the insulating film 14. The capacitive electrode layer 16 may be covered with an insulating film made of silicon nitride. An insulating film 20 made of silicon oxide is formed on the insulating film 14. The insulating film 20 has a " rectangular " opening 20a that allows the sensing portion of the piezoelectric sensor 22A to be arranged over the capacitive electrode layer 16. As shown in FIG. The insulating film 20 is formed to cover the terminal T ₃ of the capacitor electrode layer 16, where the terminal T ₃ has a connection hole 20b for exposing the contactor K ₃ . The contactor K ₃ is connected to a wiring layer (not shown) through the connection hole 20b.

The piezoelectric sensor 22A has terminals T ₁ and T ₂ which protrude from opposite sides thereof and are fixed to opposite sides of the insulating film 20, wherein the sensing section is supported by the terminals T ₁ and T ₂ . And arranged in the opening 20a. The piezoelectric sensor 22A has a first semiconductor layer 22a in which a coiled winding pattern extends inwardly at one side of the opening 20a on the insulating film 20, and at the other side of the opening 20a on the insulating film 20. A third semiconductor layer 22b having a coiled winding pattern extending inwardly, and a third semiconductor formed continuously with the inner ends of the semiconductor layers 22a and 22b and having a weight layer 24W disposed thereon. Layer 22c, wherein the terminals T ₁ and T ₂ are formed by fixing the outer ends of the semiconductor layers 22a and 22b on the insulating film 20. The sensing unit is realized by supporting the third semiconductor layer 22c by the first and second semiconductor layers 22a and 22b in a three-dimensional manner. All of the semiconductor layers 22a to 22c are made of doped polysilicon or the like, and the weighting layer 24W is made of, for example, tungsten or tungsten silicide. Tungsten is a high concentration that produces sufficient inertial mass in a relatively small pattern. The capacitance (or capacitance) is realized between the semiconductor layers 22a to 22c and the capacitor electrode layer 16.

On the right side of the second semiconductor layer 22b, the capacitor electrode layer 22X is arranged to extend in parallel with the predetermined side surface A ₁ of the opening 20a. The capacitor electrode layer 22X has a terminal T ₄ fixed on the insulating film 20. The capacitance is realized between the second semiconductor layer 22b and the capacitor electrode layer 22X. The capacitor electrode layer 22X is formed in a cantilever manner, but may be formed as a fixed electrode layer extending on the sidewall of the opening 20a or the insulating film 20.

Resistive layers 22P, 22Q, and 22R, each composed of doped polysilicon, are arranged in parallel on the insulating film 20, where they are used as a bridge circuit together with the piezoelectric sensor 22A. The resistive layers 22P, 22Q, and 22R may share some processes and be formed in common with the piezoelectric sensor 22A. For example, a doped polysilicon layer is deposited to realize an impurity concentration suitable for forming the piezoelectric sensor 22A, and then ion implantation is performed to form the resistive layers 22P, 22Q, and 22R in the doped polysilicon layer. The impurity concentration in the predetermined portion used for the formation of is adjusted.

The interlayer insulating film 26 made of silicon oxide includes resistive layers 22P, 22Q, and 22R on the insulating film 20, terminals T ₁ and T ₂ of the piezoelectric sensor 22A, and terminals of the capacitor electrode layer 22X ( T ₄ ). The interlayer insulating film 26 has an opening that coincides with the opening 20a of the insulating film 20. Accordingly, the sensing portion of the piezoelectric sensor 22A and the beam portion of the capacitive electrode layer 22X become floated in the air within the hollow, which hollow is the capacitive electrode layer 16. The opening 20a and the interlayer insulating film 26 are formed from above.

The wiring layers 28A and 28X are formed on the interlayer insulating film 26. The wiring layer 28A is connected to the contactor K ₁ of the terminal T ₁ of the piezoelectric sensor 22A through the connection hole. Similarly, the contactor K ₂ of the terminal T ₂ of the piezoelectric sensor 22A is also connected to a wiring layer (not shown). The wiring layer 28X is connected to the contactor K ₄ of the terminal T ₄ of the capacitor electrode layer 22X via a connection hole of the interlayer insulating film 26.

The wiring layers 28P, 28Q, and 28R are formed on the interlayer insulating film 26. These are connected to the contacts K ₅ , K _6, and K ₇ formed on one end of the resistive layers 22P, 22Q, and 22R, respectively, through the connection holes of the interlayer insulating film 26. Similarly, other wiring layers (not shown) are connected with the contacts K ₈ , K ₉ and K ₁₀ formed on the other ends of the resistive layers 22P, 22Q and 22R, respectively, through the connection holes of the interlayer insulating film 26. do.

A passivation insulating film (described below in connection with FIG. 6) made of silicon nitride is formed to cover the wiring layers 28A, 28X, 28P, 28Q and 28R on the interlayer insulating film 26. This passivation insulating film has an opening through which the sensing portion of the piezoelectric sensor 22A and the beam portion of the capacitor electrode layer 22X are exposed over the opening 20a.

With the main surface of the substrate 10 facing upwards, the terminals T ₁ and T ₂ and the third semiconductor layer 22c cross each other vertically on the main surface of the substrate 10 and Y It is linearly arranged in the axial direction in the Y-axis direction (consistent with the extension direction of the capacitor electrode layer 22X). Here, the third semiconductor layer 22c is displaced in response to acceleration (or vibration) in the Z-axis direction perpendicular to both the X-axis direction and the Y-axis direction as well as the main surface of the substrate 10. The third semiconductor layer 22c is also displaced in response to acceleration (or vibration) in each of the X-axis direction and the Y-axis direction. The displacement of the third semiconductor layer 22c is based on the resistance strain of the first and second semiconductor layers 22a and 22b, the capacitance strain of the capacitor electrode layer 16, and the capacitance strain of the capacitor electrode layer 22X. Can be detected. That is, the acceleration (or vibration) can be detected in a three-dimensional manner by detecting the displacement of the third semiconductor layer 22c.

FIG. 2 shows an equivalent circuit that simulates the actual operation of the physical quantity sensor 'PS' shown in FIG. 1, wherein the resistive layers 22P, 22Q and 22R and the piezoelectric sensor 22A are connected together in a bridge circuit. have. The power terminal P ₁ is connected to one end of the resistive layers 22P and 22Q, and the power terminal P ₂ is connected to one end of the resistive layer 22P and one end of the piezoelectric sensor 22A. The output terminal Q ₁ is connected to the other end of the resistive layer 22Q and the other end of the piezoelectric sensor 22A, and the output terminal Q ₂ is connected to the other end of the resistive layers 22P and 22R. By using the above-described bridge circuit, in response to resistance deformation of the first and second semiconductor layers 22a and 22b of the piezoelectric sensor 22A, an electrical signal can be extracted through the output terminals Q ₁ and Q ₂ . Can be.

The physical sensor PS includes capacitances Cz and Cx in addition to the piezoelectric sensor 22A. The capacitor Cz is formed between the capacitor electrode layer 16 and the semiconductor layers 22a to 22c, which is deformed in response to the displacement of the semiconductor layers 22a to 22c in the Z-axis direction. The capacitor Cx is formed between the capacitor electrode layer 22X and the semiconductor layer 22b and deforms in response to the displacement of the semiconductor layer 22b in the X-axis direction. Therefore, the direction in which the acceleration is applied to the physical quantity sensor PS can be distinguished with respect to the capacitance deformation of the capacitances Cz and Cx.

It is possible to deform the physical quantity sensor PS by reducing the size of the capacitive electrode layer 16 so as to form the capacitance Cz only between the capacitive electrode layer 16 and the semiconductor layer 22c. The capacitor electrode layer 22X is formed in parallel with the other side A ₂ opposite to one side A ₁ of the opening 20a and forms a capacitor Cx between the capacitor electrode layer 22X and the semiconductor layer 22a. It is also possible to modify the physical quantity sensor PS in such a way as to extend. In addition to or instead of the capacitance Cx, a capacitance for detecting displacement in the Y-axis direction can be configured.

3 to 9 show steps of manufacturing an IC device having the physical quantity sensor shown in FIG. 1, FIGS. 3 to 6 are cross-sectional views along the line A-A 'of FIG. 1, and FIGS. 7 to 9 are FIGS. 3 to 6 are cross-sectional views of the transistor related region, and the same parts as those shown in FIG. 1 are denoted by the same reference numerals, and thus detailed description thereof will be omitted.

In the first step shown in Figs. 3 and 7, a field insulating film 12 made of silicon oxide is formed on the main surface of the semiconductor substrate 10 in accordance with a selective oxidation process. As shown in FIG. 7, a MOSFET (i.e., a metal oxide semiconductor field effect transistor) TR (simply referred to as transistor TR) is an element hole 12a of the electric field insulating film 12 on the surface of the substrate 10 according to a known process. Is formed. In the transistor TR, reference numeral F denotes a gate insulating film, reference numeral G denotes a gate electrode layer, reference numerals S ₁ and S ₂ denote side spacers, reference numeral S denotes a source region; Reference numeral D denotes a drain region. Incidentally, it is possible to form the electric field insulating film 12 according to the so-called shallow trench isolation (STI) method, which is formed as a shallow trench and is formed by a chemical vapor deposition (CVD) method. It consists of an insulating film which consists of silicon oxide formed. In consideration of the influence on the substrate 10, it is preferable to form a relatively large shallow trench under the capacitor electrode layer 16 using a relatively large pattern.

Next, an insulating film 14 composed of silicon oxide or doped silicon oxide (PSG (i.e., phosphoric silicate glass), BSG (i.e., borosilicate glass), BPSG (i.e., borosilicate glass), etc.) is provided with a transistor TR and an electric field. In order to cover the insulating film 12, it is formed by the CVD method. The insulating film 14 is used as a pad film, the thickness of which is in the range of 20 nm to 500 nm, preferably set to 100 nm.

Next, the capacitor electrode layer 16 is formed on the insulating film 14. That is, a predetermined electrode material such as doped polysilicon, metal or metal silicide is deposited on the surface of the substrate 10 and then patterned by photolithography and dry etching. As electrode material, it is possible to use a laminate material using two or more elements selected from doped polysilicon, metal and metal silicide. As the metal, it is possible to use aluminum and an aluminum alloy. Alternatively, it is possible to use rare metals such as gold and silver, tungsten, and high melting point metals such as molybdem and titanium. The polysilicon is bonded by the CVD method, and the metal or silicide may be bonded by sputtering.

Next, an insulating film 18 made of silicon nitride is formed by the CVD method to cover the capacitive electrode layer 16 on the insulating film 14. The insulating film 18 is used as an etching stopper film in another step shown in FIG. 6, and the thickness is in the range of 50 nm to 350 nm, preferably set to 140 nm. Incidentally, it is possible to omit the insulating film 18 when the capacitor electrode layer is made of a polysilicon layer.

In the second step shown in FIGS. 4 and 8, an insulating film 20 composed of silicon oxide or doped silicon oxides (PSG, BSG and BPSG) is formed on the insulating film 18 according to the CVD method. Here, BPSG and PSG have a high etching rate, so that etching can be easily performed. The insulating film 20 serves as a sacrificial film to assist in the formation of the opening 20a shown in FIG. 1, and the thickness thereof is in the range of 100 nm to 1000 nm, preferably in the range of 500 nm to 800 nm. Preferably it is set to 650 nm. The insulating film 20 does not necessarily need to be formed by the CVD method, that is, it may be composed of a silicon oxide film that can be formed by a spin coat method, that is, SOG (spin on glass). SOG has a larger etching rate compared to BPSG and is suitable as a sacrificial film that can be easily removed. SOG is annealed as needed (at a high temperature in the range of 350 ° to 800 °), whereby the etching rate can be adjusted.

When the insulating films 14, 18, and 20 are stacked together, as shown in Fig. 8, the connection holes 20 _S and 20 _{D form} the source region S and the drain region of the transistor TR in accordance with photolithography and dry etching. It is formed corresponding to (D). Next, a polysilicon layer 22 composed of doped polysilicon is formed by CVD to cover the connection holes 20 _S and 20 _D on the insulating film 20. The polysilicon layer 22 is used in the formation of the semiconductor layers 22a-22c, the capacitor electrode layers 22X, and the resistive layers 22P, 22Q, and 22R, which operate as components of the physical quantity sensor, and also includes the transistor TR. It is used to form the source electrode region 22S, the drain electrode region 22D, and the wiring layer 22K (see Fig. 9) in the transistor related region, and the thickness is in the range of 100 nm to 2000 nm, preferably 500 It is set to nm.

In the third step shown in Figs. 5 and 9, since the polysilicon layer 22 is patterned by photolithography and dry etching, the semiconductor layers 22a-22c, the capacitive electrode layer 22X, and the resistive layers 22P and 22Q. And 22R, the source electrode layer 22S, the drain electrode layer 22D, and the wiring layer 22K can be formed. Tungsten is used as the weight realization metal covering the above-described layers 22a-22c, 22X, 22P-22R, 22S, 22D and 22K on the insulating film 20, which is used for sputtering or CVD (preferably for the formation of thick films). The tungsten layer is then formed, which is then patterned by photolithography and dry etching to form the weighting layer 24W, the source electrode layer 24S, the drain electrode layer 24D, and the wiring layer 24K. Here, the weighting layer 24W is formed on the semiconductor layer 22c, the source electrode layer 24S is formed on the source electrode layer 22S, and the drain electrode layer 24D is formed on the drain electrode layer 22D. . The thickness of the tungsten layer is in the range of 500 nm to 1000 nm, and is preferably set to 500 nm.

In the above description, the polysilicon layer 22 is patterned, and then the tungsten layer is patterned. Of course, it is also possible to change the patterning order between these layers. That is, a tungsten layer may be formed on the polysilicon layer 22 and then patterned, after which the polysilicon layer 22 may be patterned. A weight realization metal used to form the weighting layer 24W, which is a relatively heavy metal suitable for other metals (other than tungsten), i.e. heavy metals (e.g., Ta, Hf, Ir, Pt, and Au), Si For example, it is also possible to use low resistance metals (eg Ti, Cr, Ni, Co and Cu) that are heavier than Zr, Nb, Mo and Pd) and Si.

In the fourth step shown in Figs. 6 and 9, an insulating film 26 made of silicon oxide is formed on the insulating film 20, the above-described layer, semiconductor layers 22a-22c, capacitor electrode layer 22X, and resistive layer 22P. -22R), the source electrode layers 22S and 24S, the drain electrode layers 22D and 24D, the wiring layers 22K and 24K, and the weighting layer 24W. It is preferable that spin-on glass or hydrogen silsesquioxane undergo a rotational application to form a film, followed by heat treatment to form an insulating film 26 with good flatness. The insulating film 26 is etched together with the insulating film 20 in the next step, and therefore the insulating film 26 is preferably made of a predetermined material whose etching rate is almost the same as that of the insulating film 20. Of course, it is also possible to reduce the etching rate of the insulating film 20 to be slightly lower than the etching rate of the insulating film 26. This makes it possible to realize a good etching execution shape so that no watermark remains during cleaning and drying. Next, a passivation insulating film 29 made of silicon nitride is formed on the insulating film 26 by the CVD method.

Next, a resist layer having holes is formed by photolithography on the insulating film 29, and then dry etching is performed using the resist layer as a mask to selectively remove a predetermined portion of the insulating film 29, This forms the opening 29a. Thereafter, an isotropic wet etching is performed using the insulating film 29 having the resist layer and the opening 29a (previously used for dry etching) as a mask to draw the opening 26a with respect to the insulating film 26, and the insulating film ( The opening 20a is formed with respect to 20). The opening 26a is formed continuously to the opening 29a, and the opening 20a is formed continuously to the opening 26a. As a result, as shown in FIG. 6, the coiled portions of the semiconductor layers 22a and 22b and the beam portions of the semiconductor layer 22c (with the weighting layer 24W) and the capacitive electrode layer 22X are the openings 20a. And a floating state in the entire hollow space realized by 26a) and is exposed to the opening 29a. After completion of the isotropic wet etching, the resist layer is removed by a known method. For example, it is possible to use buffered hydrofluoric acid for isotropic wet etching. Incidentally, isotropic wet etching can be replaced with isotropic dry etching. In this case, the insulating film 20 is made of BPSG and the insulating film 26 is made of SOG which is cured at 400 ° C. At this time, the laminate of the insulating films 20 and 26 is formed by reactive ion etching (RIE) or chemical dry etching ( CDE). Here, RIE uses a CF ₄ + O ₂ gas and CDE uses a CHF ₃ gas.

The resist layer may be removed immediately after dry etching. Here, isotropic wet etching is performed using only the insulating film 29 which has the opening 29a as a mask.

Next, modifications of the manufacturing method described above with reference to FIGS. 2 to 9 will be described with reference to FIGS. 10 to 12, and the same parts as those shown in FIGS. 2 to 9 are denoted by the same reference numerals. Description thereof will be omitted. The modification is characterized in that the source electrode layer 24S and the drain electrode layer 24D are formed at the same time, and these layers serve as the contact layer as well as the weighting layer 24W of the transistor TR.

In a variant shown in FIG. 10 similar to the second step shown in FIG. 4, after completion of the first step shown in FIG. 3, an insulating film 20 composed of silicon oxide or doped silicon oxides (PSG, BSG and BPSG) ) Is formed on the insulating film 18, and a polysilicon layer 22 made of doped polysilicon is formed on the insulating film 20.

In a variant shown in FIG. 11 similar to the third step shown in FIG. 5, the polysilicon layer 22 is patterned by photolithography and dry etching to form the wiring layer 22K, wherein in FIG. As shown, the semiconductor layers 22a-22c, the capacitor electrode layers 22X, and the resistive layers 22P-22R are formed on the insulating film 20 on the substrate 10.

Next, a resist layer 21 is formed by photolithography so as to cover the wiring layer 22K, the semiconductor layers 22a-22c, the capacitor electrode layer 22X, and the resistive layer 22P-22R on the insulating film 20. The resist layer 21 has a hole corresponding to the source connection hole 20 _S and the drain connection hole 20 _D. At this time, by using the resist layer 21 is running dry etching using as a mask the source connection hole (20 _S) and a drain connected to the hole (20, _D) a laminate of a source region (S) of the insulating film (14, 18 and 20) And the drain region D. Thereafter, the resist layer 21 is removed.

The in variation, the tungsten layer 24, a connection hole (20 _S and 20 _D) acting in the weighted achieve metal layers shown in Figure 12, the wiring layer (22K), the semiconductor layer (20a-20c), the capacity electrode layer (22X), And sputtering or CVD to cover the resistive layers 22P-22R. Alternatively, a barrier metal layer corresponding to the stack of Ti and TiN layers may be formed prior to the formation of the tungsten layer 24, such that the tungsten layer is formed over the barrier metal layer.

Next, first and second resist layers having a pattern corresponding to the wiring layer 22K and the semiconductor layer 22c are formed on the tungsten layer 24 by photolithography.

Next, dry etching is performed on the tungsten layer 24 using the first and second resist layers as masks, so that the tungsten layer is subjected to an "etch back", where the barrier metal layer is the source electrode layer 24S, the drain. In order to form the electrode layer 24D, the wiring layer 24K, and the wiring layer 24W, an etching back is performed as needed. A source electrode (24S) and drain electrode (24D) is connected to the source region (S) and a drain region (D) through the connection hole (20 _S and 20 _D), respectively (see Fig. 11). Here, the wiring layer 24K and the weight layer 24W are formed on the wiring layer 22K and the semiconductor layer 22c, respectively.

Then, similar to the fourth step shown in Figs. 6 and 9, insulating films 26 and 29 are formed, and openings 29a, 26a, and 20a are formed.

According to the manufacturing method described above with reference to FIGS. 3 to 12, an IC device (see FIG. 1) including a physical quantity sensor and a peripheral circuit thereof can be easily manufactured according to a semiconductor manufacturing process. According to the modification shown in Figs. 10 to 12, the electrode layers (or contact layers) 24S and 24D are formed using W plugs having low resistance, so that the transistor characteristics can be further improved.

13 shows a physical quantity sensor according to a second embodiment of the present invention, which is designed to be suitable for the detection of the inclination of the substrate.

The insulating film 30 made of silicon oxide passes through an electric field insulating film (corresponding to the insulating film 12) and a pad insulating film (corresponding to the insulating film 14) and a semiconductor substrate (similar to the semiconductor substrate 10 shown in FIG. 1). It is formed on the main surface of, which has a rectangular opening 30a which allows six piezoelectric sensors X _L , X _M , X _S , Y _L , Y _M and Y _S to be arranged therein.

Six capacitive electrode layers C _L , C _M , C _S , D _L , D _M and D _S are insulated from the bottom of the opening 30a formed by four sides A ₁₁ , A ₁₂ , A ₁₃ and A ₁₄ . (30) is arranged on the pad insulating film immediately below. Similar to the capacitive electrode layer 16, the capacitive electrode layers C _L , C _M , C _S , D _L , D _M, and D _S are each composed of doped polysilicon or metal, and these are formed of an insulating film composed of silicon nitride ( Corresponding to the insulating film 18). The capacitive electrode layers C _L , C _M , C _S , D _L , D _M and D _S are arranged opposite to X _L , X _M , X _S , Y _L , Y _M and Y _S , respectively It is formed in a rectangular pattern consistent with X _L , X _M , X _S , Y _L , Y _M and Y _S.

The capacitor electrode layer C _L has a terminal Tc extending outward from the side surface A ₁₁ of the opening 30a on the pad insulating film directly under the insulating film 30, and the terminal Tc is directly under the insulating film 30. It has a contactor Kc on the pad insulating film. The contactor Kc of the terminal Tc is connected to a wiring layer (not shown) via a connection hole formed in the insulating film 30. Similar to the capacitive electrode layer C _L , the other capacitive electrode layers C _M , C _S , D _L , D _M and D _S also have terminals with contacts, which are each connected with a wiring layer (not shown).

Piezoelectric sensors (X _L, X _M and X _S) is formed in a respective cantilever, which is arranged with respect to (the opposite to the side surface (A ₁₂₎₎ side (A ₁₃₎ of the opening (30a) side (A ₁₃ ) opening (30a) from the side surface (a ₁₁₎ parallel to the insulating layer 30 and adjacent to and extends inwardly. The piezoelectric sensor X _L includes the first semiconductor layer 32 and the second semiconductor layer 34 extending from the insulating film 30 into the opening 30a, and the semiconductor layers 32 and 34 in the opening 30a. And a third semiconductor layer 36 which is formed continuously at the distal end portion and has a weighting layer 38 fixed thereon. The other ends of the semiconductor layers 32 and 34 are fixed on the insulating film 30 to form terminals T ₁₁ and T ₁₂ . Thus, the sensing portion of the physical quantity sensor is configured such that the semiconductor layers 32 and 34 support the semiconductor layer 36 to realize three-dimensional displacement. All semiconductor layers 32, 34, and 36 are made of doped polysilicon, and weighting layer 38 is made of tungsten. The capacitive electrode layer C _L and the semiconductor layer 36 form a capacitance (or capacitance). The displacement of the semiconductor layer 36 is detected based on the resistance deformation of the semiconductor layers 32 and 34 and the capacitance deformation of the capacitor electrode layer C _L due to the piezoresistive effect.

Piezoelectric sensors (X _M X and _S), only have a configuration similar to that of the piezoelectric sensor (X _L), which the length of non-pregnant women, which overlaps the opening (30a) in plan view different from the piezoelectric sensor (X _L). That is, the piezoelectric sensors X _L , X _M , and X _S have a beam length that overlaps the opening 30a in plan view with X _L being the longest beam length, X _M being the intermediate beam length, and X _S being the shortest beam. They are different in length. The piezoelectric sensor X _M has a "weighted" semiconductor layer formed at the tip of the beam portion and having a weighting layer thereon, similar to the piezoelectric sensor X _L having the semiconductor layer 36. An electrostatic capacity (or capacity) is formed between the weighted semiconductor layer and the capacitive electrode layer C _M of the piezoelectric sensor X _M. Similarly, the piezoelectric sensor X _S has a "weighted" semiconductor layer formed at the tip of its beam and having a weighting layer thereon. A capacitance (or capacitance) is formed between the weighted semiconductor layer and the capacitor electrode layer C _S of the piezoelectric sensor X _S. In each of the piezoelectric sensors X _M and X _S , the resistance deformation and the correspondence of the two semiconductor layers (similar to the semiconductor layers 32 and 34 of the piezoelectric sensor X _L ) in which the displacement of the weighted semiconductor layer forms a beam portion Is detected based on the capacitance deformation of the capacitive electrode layers (i.e., C _M and C _S ).

With respect to all the piezoelectric sensors (Y _L, Y _M, and Y _S) is formed in a cantilever manner, which side opposite to the side surface (A ₁₁₎ of the opening (30a) (A _14), adjacent to a side (A ₁₄₎ It extends inwardly from the insulating film 30 to the opening 30a in parallel with the side surface A ₁₂ . Piezoelectric sensors (Y _L, Y _M, and Y _S) is a piezoelectric sensor (X _L, X _M, and X _S) and is configured similarly, each of the beam length which overlaps the opening (30a) in plan view the piezoelectric sensor X _L Is equal to the beam length of X _M , and X _S.

The piezoelectric sensors Y _L , Y _M and Y _S have a weighted semiconductor layer (similar to the semiconductor layer 36 of the piezoelectric sensor X _L ) at the tip of the beam portion, and the weighted semiconductor layer and the capacitive electrode layer ( Capacity is formed between D _L , D _M and D _S ), respectively. In each piezoelectric sensor Y _L , Y _M and Y _S , the displacement of the weighted semiconductor layer is the resistance deformation of the two semiconductor layers (similar to the semiconductor layers 32 and 34) that realize the beams and the corresponding capacitive electrode layer ( That is, it is detected based on the dose variation of D _L , D _M , and D _S ).

The capacitive electrode layers C _L , C _M , C _S , D _L , D _M and D _S respectively correspond to piezoelectric sensors X _L , X _M , X _S , Y _L , Y _M and Y _S independently of one another. Are arranged. The capacitive electrode layers C _L and D _L are connected together by connecting with the piezoelectric sensors X _L and Y _L , and the capacitive electrode layers C _M and D _M are connected together with the piezoelectric sensors X _M and Y _M. The present invention can be modified so that the capacitive electrode layers C _S and D _S are interconnected and connected with the piezoelectric sensors X _S and Y _S to be interconnected together.

In the state where the main surface of the substrate 10 is horizontally supported, the piezoelectric sensors X _L , X _M and X _S extend in the Y axis direction perpendicular to the X axis direction parallel to the main surface of the substrate 10. It is assumed that In this case, the substrate 10 may be rotated about an axis of rotation lying parallel to the X-axis direction so that the substrate 10 may be inclined as shown by the dotted line arrow Y ', and the substrate 10 may be inclined with the Y-axis direction. The substrate 10 may be inclined as shown by the dashed arrow X 'by rotating about the axis of rotation lying in parallel. Thereafter, the inclination of the inclined substrate 10 as shown by the dotted arrow Y 'is referred to as "X-axis inclination", and the inclination of the inclined substrate 10 as shown by the dotted arrow X' is shown. Slope is referred to as "Y axis slope".

Table 1 shows the magnitudes of the resistances and capacitances of the piezoelectric sensors X _L , X _M and X _S with respect to the X and Y axis inclinations, respectively. For the piezoelectric sensor X _L , for example, "R" represents the sum of the resistances of the semiconductor layers 32 and 34, and "C" represents the capacitance formed between the semiconductor layer 36 and the capacitor electrode layer C _L. Indicates. Three angles of inclination, 0 °, 45 ° and 90 °, are listed in Table 1 with respect to the X and Y axis inclinations, where "0 ° inclination" is the horizontal state of the major surface of the substrate 10. Indicates.

sensor Tilt angle X-axis slope Y axis slope R C R C X _L 0 ° MAX Short MAX Short 45 ° MID MID Smaller Smaller 90 ° MIN MIN Smaller Smaller X _M 0 ° MID MAX MID MID 45 ° MIN MID Smaller Smaller 90 ° - - X _S 0 ° MIN MID MIN MIN 45 ° - MIN - 90 ° - - -

In Table 1, "MAX", "MID", and "MIN" represent "maximum", "medium", and "minimum", respectively. The sign "-" indicates that there is no change in resistance or capacity regardless of the increase in the inclination angle. &Quot; Short " indicates a short circuit condition where the weighted semiconductor layer (e.g. 36) at the tip of the beam portion of the piezoelectric sensor is in contact with the capacitive electrode layer (e.g. C _L ). "Smaller" indicates that the resistance strain or the capacity strain occurring at the Y-axis tilt is smaller than that occurring at the X-axis tilt. Incidentally, the total capacitance of the physical quantity sensor is increased in response to the displacement applied in the direction with respect to the lower side of the substrate, that is, in the negative direction of the Z axis, while the positive capacity of the physical quantity sensor is applied in the direction with respect to the upper side of the substrate, that is, in the positive direction of the Z axis. It decreases in response to the displacement. Therefore, the three-dimensional displacement including the X-axis inclination, the Y-axis inclination and the Z-axis inclination can be detected by the physical quantity sensor of the present embodiment.

Table 1 shows that the resistance deformation of the piezoelectric sensor decreases as the length of the beam portion overlapping the opening 30a in the plan view decreases, where the resistance deformation of the piezoelectric sensor X _M is a piezoelectric sensor X _L. ), And the resistance deformation of the piezoelectric sensor X _S is smaller than that of the piezoelectric sensor X _M. For example, for the piezoelectric sensor X _L , both resistance and capacity are represented as “MID” at 45 ° of X axis inclination, while resistance and capacity are both higher at 45 ° of X axis incline at 45 ° of Y axis. Smaller This is because the semiconductor layer 36 is displaced only in a predetermined direction perpendicular to the main surface of the substrate 10 at the X-axis inclination, whereas at the Y-axis tilt, the semiconductor layer 36 is perpendicular to the main surface of the substrate 10. This is because they are bidirectionally displaced in a predetermined direction and a direction applied in the X-axis direction. Therefore, it becomes possible to detect the inclination angle and the inclination direction based on the combination of the electrical signals representing the resistance deformation and the capacitance deformation of the piezoelectric sensors X _L , X _M and X _S , wherein the electrical signal is, for example, plus Will go through.

Incidentally, replace "X _L ", "X _M ", and "X _S " with "Y _L ", "Y _M ", and "Y _S ", and replace "X-axis slope" with "Y-axis slope" By replacing "Y-axis inclination" with "X-axis inclination", thereby causing "Smaller" to indicate that the resistive or capacitive deformation occurring at the X-axis inclination is smaller than that occurring at the Y-axis inclination, Similar tables for the piezoelectric sensors Y _L , Y _M and Y _S can be easily formed by partially rewriting the contents of Table 1. With reference to this table, the resistance strain and the capacitance strain can be obtained in response to the Y-axis inclination and the X-axis inclination with respect to each of the piezoelectric sensors Y _L , Y _M, and Y _S. Similar to piezoelectric sensors X _L , X _M and X _S , the tilt angle and the tilt direction are detected based on a combination of electrical signals representing the resistance deformation and the capacitance deformation of piezoelectric sensors Y _L , Y _M and Y _S. It is possible, where the electrical signal is, for example, added. In addition, the deformation of the signal can be detected in response to the acceleration applied to the physical quantity sensor. For example, the acceleration or deceleration may be calculated by a calculation circuit (arranged on or outside the substrate) based on the time-dependent deformation of the output of the physical quantity sensor that is kept constant during constant accelerated movement. .

In Fig. 13, the physical quantity sensors using the piezoelectric sensors X _L , X _M and X _S and the piezoelectric sensors Y _L , Y _M and Y _S arranged on the same substrate have an X-axis tilt and a Y-axis tilt applied thereto. Can be detected accurately. This physical quantity sensor can be easily manufactured according to the above-described semiconductor manufacturing process described with reference to FIGS. 3 to 12.

Both physical quantity sensors have conductive weights realized by stacking weighting layers (e.g., 24W or 38) on a semiconductor layer (e.g., 16 or 36). Of course, it is also possible to implement a conductive weighting portion by laminating a semiconductor layer on the weighting layer. Alternatively, the weight layer may be omitted by increasing the thickness of the semiconductor layer to have a weighting function. In addition, it is also possible to process two conductive layers (e.g., 22a and 22b, or 32 and 34) by treating a conductive layer (e.g., tungsten layer) having a weighting function.

Next, a third embodiment of the present invention will be described with reference to FIGS. 15 to 17, which show a bearing sensor constructed by combining a physical quantity sensor and a magnetic sensor, in which the figures 1, 5, And the same parts as shown in Fig. 6 are denoted by the same reference numerals. As the magnetic sensor, it is possible to use a magnetoresistive element such as a giant magnetoresistive element (or a GMR element). Specifically, as shown in FIG. 15, the X-axis magnetic sensor 100X and the Y-axis magnetic sensor 100Y are on the periphery of the physical quantity sensor (similar to the physical quantity sensor shown in FIG. 1) on the same substrate 10. Arranged in different positions, where each magnetic sensor comprises two or more GMA elements whose sensing directions cross each other, bearing based on a variation in resistance of the GMA elements in response to a magnetic field applied from the outside towards them This is determined.

The manufacturing method for the bearing sensor shown in FIG. 15 is similar to the manufacturing method mentioned above for the physical quantity sensor. Therefore, the technical features regarding the magnetic sensor 100 (representing magnetic sensors 100X and 100Y) are described below.

The diagram of FIG. 15 is drawn by partially changing the diagram of FIG. 5 with respect to a method of manufacturing an IC device including a physical quantity sensor, wherein a magnetic sensor composed of permanent magnets and GMR elements (see '22G') ( 100 is further formed on the same substrate 10 together with the preceding elements of the physical quantity sensor. The magnetic sensor 100 is formed and then undergoes patterning after the formation of the passivation film 29.

The GMR element consists of PtMn, CoFe, Cu, CoFe, NiFe, and CoZrNb, which are sequentially stacked together from top to bottom. In addition, the GMR element is composed of a spin-valve film composed of a free layer, a spacer layer, and a fixed layer, where the permanent magnet has a bias field in the free layer to maintain uniaxial anisotropy. Add.

Thereafter, the second passivation film 31 made of SiN or SiON and the protective film 32 made of polyimide are sequentially formed as shown in FIG.

As shown in FIG. 17, an opening is formed through the second passivation film 31 and the protective film 32 with respect to the physical quantity sensor, so that the aforementioned capacitive electrode layers and the weighting layer are exposed in the cavity.

The bearing sensor of this embodiment is designed such that two magnetic sensors (eg, '100X' and '100Y') are arranged in close proximity to each other along adjacent sides of the physical quantity sensor. Of course, it is also possible to arrange four magnetic sensors, connected together to form a bridge circuit, along four sides of the physical quantity sensor.

When the bearing sensor is tilted, it is possible to use the output of the physical quantity sensor to compensate the output of the magnetic sensor. Thus, it is possible to accurately determine the bearing. In addition, this embodiment is preferably applied for applications that require sensing capability with respect to both inclination and bearing.

Since the present invention can be embodied in various forms without departing from the spirit or core characteristics thereof, the present embodiments are descriptive and not restrictive, which is not to be construed as the scope of the present invention by the foregoing claims. This is because it is limited by the range. All changes that come within the scope of the claims or their equivalents are intended to be covered by the claims.

The present invention realizes a compact physical quantity sensor that can reduce physical chip size to detect physical quantities such as acceleration, vibration, and inclination in a two-dimensional or three-dimensional manner. Since this physical quantity sensor is constructed using a capacitive type piezoelectric sensor basically composed of a semiconductor layer, it can be easily manufactured by a semiconductor manufacturing process. Therefore, the physical quantity sensor can be easily integrated together in the peripheral circuit or the signal processing circuit.

Claims (5)

As a physical quantity sensor, Substrate, An insulating film having an opening formed to partially expose a main surface of the substrate; A plurality of piezoelectric sensors each having two terminals, each piezoelectric sensor being configured such that the sensing portion is arranged in the opening while being supported by the two terminals attached on the insulating film at different positions around the opening; The piezoelectric sensor of has a first semiconductor layer having a coiled winding pattern extending into the opening from the periphery of the opening and a second semiconductor having a coiled winding pattern extending into the opening from the periphery of the opening of the insulating film. A layer and a conductive weighting portion interconnecting the inner ends of the first and second semiconductor layers in the opening, whereby the outer ends of the first and second semiconductor layers attached on the insulating film are separated from each other. Used to form a terminal, and wherein the conductive weighting portion is negative in the opening by the first and second semiconductor layers. And, - state also realize three-dimensional displacement is supported by a (floating manner) A capacitive electrode layer arranged at the bottom of the opening on the main surface of the substrate and establishing a capacitance between itself and the conductive weighting portion, The physical quantity sensor of which the displacement of the said conductive weight part is detected based on the variation amount of the resistance of the said 1st and 2nd semiconductor layer, and the variation amount of the said capacitance. The semiconductor device of claim 1, further comprising a second capacitance electrode layer having one end fixed to the insulating layer and establishing a second capacitance with respect to the first and second semiconductor layers, wherein the displacement of the conductive weighting portion is equal to the second capacitance. Physical quantity sensor detected based on the variation amount. The physical quantity sensor of claim 1, wherein outer ends of the first and second semiconductor layers are attached at opposing positions in the opening of the insulating film. As a physical quantity sensor, Substrate, An insulating film having an opening formed to partially expose a main surface of the substrate; A plurality of piezoelectric sensors each having two terminals and a sensing unit, wherein the sensing unit is supported in a floating state in an opening by the two terminals attached to different positions around the opening of the insulating film, each piezoelectric sensor being insulated from the insulating film First and second semiconductor layers extending parallel to each other from the periphery of the opening inward to the opening, and conductive weights interconnecting the inner ends of the first and second semiconductor layers in the opening, thereby Outer ends of the first and second semiconductor layers are attached on the insulating film to form the two terminals, the conductive weights are supported by the first and second semiconductor layers to realize a three-dimensional displacement; and , A capacitive electrode layer arranged at the bottom of the opening on the main surface of the substrate to establish a capacitance between itself and the conductive weighting portion, The physical quantity sensor of which the displacement of the said conductive weight part is detected based on the variation amount of the resistance of the said 1st and 2nd semiconductor layer, and the variation amount of the said capacitance. As a physical quantity sensor, Substrate, An insulating film having an opening formed to partially expose a main surface of the substrate; A plurality of piezoelectric sensors each having a sensing section and two terminals, the sensing sections being cantilevered in relation to the opening, each piezoelectric sensor extending in parallel to each other inwardly from the periphery of the opening of the insulating film; First and second semiconductor layers, and conductive weights interconnecting the inner ends of the first and second semiconductor layers in the opening, whereby the outer ends of the first and second semiconductor layers are connected to the two; Attached to the insulating film to form a terminal, the conductive weighting portion being supported by the first and second semiconductor layers to realize a three-dimensional displacement; A plurality of capacitive electrode layers arranged at the bottom of the opening on the main surface of the substrate and respectively establishing capacitance between itself and the conductive weighting portion, The physical quantity sensor of which the displacement of the said conductive weight part is detected based on the variation amount of the resistance of the said 1st and 2nd semiconductor layer, and the variation amount of the said capacitance.

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